From 6343944bc1050dcec7c959f484ee0fb6928db3be Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Fri, 30 Jun 2017 13:07:56 +0300 Subject: [PATCH] net: convert neigh_params.refcnt from atomic_t to refcount_t refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- include/net/neighbour.h | 6 +++--- net/core/neighbour.c | 8 ++++---- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/include/net/neighbour.h b/include/net/neighbour.h index e5ee739d2b8c..afc39e3a3f7c 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -77,7 +77,7 @@ struct neigh_parms { void *sysctl_table; int dead; - atomic_t refcnt; + refcount_t refcnt; struct rcu_head rcu_head; int reachable_time; @@ -396,12 +396,12 @@ void neigh_sysctl_unregister(struct neigh_parms *p); static inline void __neigh_parms_put(struct neigh_parms *parms) { - atomic_dec(&parms->refcnt); + refcount_dec(&parms->refcnt); } static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) { - atomic_inc(&parms->refcnt); + refcount_inc(&parms->refcnt); return parms; } diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 0c78c8e0409d..e31fc11a8000 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -709,7 +709,7 @@ static void neigh_parms_destroy(struct neigh_parms *parms); static inline void neigh_parms_put(struct neigh_parms *parms) { - if (atomic_dec_and_test(&parms->refcnt)) + if (refcount_dec_and_test(&parms->refcnt)) neigh_parms_destroy(parms); } @@ -1479,7 +1479,7 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev, p = kmemdup(&tbl->parms, sizeof(*p), GFP_KERNEL); if (p) { p->tbl = tbl; - atomic_set(&p->refcnt, 1); + refcount_set(&p->refcnt, 1); p->reachable_time = neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME)); dev_hold(dev); @@ -1542,7 +1542,7 @@ void neigh_table_init(int index, struct neigh_table *tbl) INIT_LIST_HEAD(&tbl->parms_list); list_add(&tbl->parms.list, &tbl->parms_list); write_pnet(&tbl->parms.net, &init_net); - atomic_set(&tbl->parms.refcnt, 1); + refcount_set(&tbl->parms.refcnt, 1); tbl->parms.reachable_time = neigh_rand_reach_time(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME)); @@ -1796,7 +1796,7 @@ static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms) if ((parms->dev && nla_put_u32(skb, NDTPA_IFINDEX, parms->dev->ifindex)) || - nla_put_u32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt)) || + nla_put_u32(skb, NDTPA_REFCNT, refcount_read(&parms->refcnt)) || nla_put_u32(skb, NDTPA_QUEUE_LENBYTES, NEIGH_VAR(parms, QUEUE_LEN_BYTES)) || /* approximative value for deprecated QUEUE_LEN (in packets) */ -- 2.20.1